Former Smash Mouth lead singer Steve Harwell died early Monday at his home in Boise, Idaho, a representative confirmed to CBS News. He was 56.

The artist — whose band is best known for the 1999 hit "All Star"  — had been in hospice care, according to representative Robert Hayes. 

The cause of death was acute liver failure, Hayes said in a statement.

"He was surrounded by family and friends and passed peacefully and comfortably," Hayes said Monday.

Harwell retired from Smash Mouth in 2021, and the band continues to tour with new vocalist Zach Goode. Smash Mouth has sold over 10 million albums worldwide and had No. 1 hit singles, five Top 40 singles and a Grammy nomination.

Formed in 1994, Smash Mouth released two platinum albums, 1997's "Fush Yu Mang" and 1999's "Astro Lounge," which featured the chart-topping  "All Star." 

Smash Mouth's first hit "Walkin' on the Sun" and a cover of the Monkees song "I'm a Believer" have garnered hundreds of millions of streams since their releases.

But it was the infectious "All Star" — which was featured on the soundtrack of the 2001 blockbuster "Shrek" — that will forever be linked with Harwell and Smash Mouth.

"Nobody else could have sang that song." Harwell told Rolling Stone in 2019. "It would have never been what it is now. I could've pitched that song to a million bands and they would have tried to do it, and it would've never been what it is."

Harwell was previously diagnosed with cardiomyopathy, a form of heart disease.

He will be cremated in Boise and buried in San Jose, California, Hayes said.  

"His only tools were his irrepressible charm and charisma, his fearlessly reckless ambition, and his king-size cajones," Hayes said. "Steve lived a 100% full-throttle life. Burning brightly across the universe before burning out."  

On Monday afternoon, Smash Mouth posted on X, the social media website formerly known as Twitter, about Harwell's death.

"Steve Harwell was a true American Original. A larger than life character who shot up into the sky like a Roman candle. Steve will be remembered for his unwavering focus and impassioned determination to reach the heights of pop stardom. Rest in peace knowing you aimed for the stars, and magically hit your target. Rest easy."

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Stephen Smith

Stephen Smith is a senior editor for CBSNews.com.